Minimally-invasive medical therapies are increasingly gaining importance. In the treatment of coronary heart disease, the surgical bypass operation on the heart is clearly declined in favor of balloon dilation (PTCA=percutaneous transluminal coronary angioplasty) and the insertion of a stent. In arterial fibrillation, ablation in the atrium has established itself in recent years. Minimally-invasive procedures are also clearly increasing in the fields of biopsies, spinal column therapies and tumor ablation.
Medical imaging that shows the vessels, organs and medical instruments in the organism in real time remains a requirement in all minimally-invasive interventions. Image artifacts thereby arise due to body and organ movement (for example due to breathing). For example, given a lung tumor the tumor moves between 1 and 2 cm during one breathing cycle.
Modern imaging devices such as computer tomographs have what is known as respiration gating; the breathing cycle is thereby taken into account in the image reconstruction, and the radiologist acquires exposures in which the movement artifacts that arise due to breathing have been corrected.
A solution which takes into account the respiratory movement in radiation therapy is known from U.S. Pat. No. 5,764,723, “Apparatus and Method to Gate a Source for Radiation Therapy”.
In biopsies or tumor ablation, the therapy needle must still be introduced manually by the physician into the organ area to be treated. For this the patient is required to hold his breath, or the physician attempts to insert the needle while estimating the breathing cycle. This method is very dependent on the cooperation of the patient and the manual/surgical skill of the physician.
The solution described in pending Siemens AG German Patent Application 2008P0365 DE, (“Movement-Controlled, in Particular Breathing-Controlled Needle Guidance”), improves the guidance of rigid instruments in an organism and reduces the requirements for the cooperation readiness of the patient or the skillfulness of the physician. However, one disadvantage is that the respiratory movement of the patient must be correctly detected.